1. Field of the Invention
The present invention relates to equipment used to control flows of air and water to fittings used to combine air with pressurized water streams for aeration, hydrotherapy, and like purposes, and especially to vertical-axis, one-way flow valves for low pressure applications.
2. The Prior Art
Hydrotherapy fittings for aerating streams of water directed into a pool or bath of water below the surface thereof are shown in U.S. Pat. Nos. 3,297,025 and 3,905,358. In such devices, a stream of water is introduced into a nozzle submerged in the body of water. An air inlet zone about the periphery of the nozzle or, in the later-issued patent, in the center of the nozzle, is connected to atmosphere and draws air by venturi action into the stream of water. The air emerges from the nozzle as bubbles within the stream of water, to provide a vigorous massage of the body of the bather. During normal operation of the hydrotherapy or whirlpool bath, if the nozzle outlet is blocked with a hand or foot or with a wash rag, the water pressure will back up water into the air line, normally necessitating that the air line be connected to a drain over flow or back into the pool of water. Even in such arrangements, blockage of the nozzle can create a spray from the top of the air intake line, undesirably wetting adjacent areas. While one-way flow check valves are known generally in the art, no simple, inexpensive, and light weight check valve specifically adapted for use with the peculiar requirements of hydrotherapy nozzles is generally available.